baseservlet.java

自己编写的一个JSP+SERVER的框架, 实际项目已经运用多次,效率很好.

package com.aptech.control.servlet;
import java.io.IOException;
import java.util.List;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import com.aptech.business.dm.BaseDM;
import com.aptech.business.exception.FatalException;

/**
 * Servlet基类
 * @author justin 2007-1-5
 *
 */
public abstract class BaseServlet extends HttpServlet {

	/**
	 * Constructor of the object.
	 */
	public BaseServlet() {
		super();
	}

	/**
	 * Destruction of the servlet. <br>
	 */
	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

	/**
	 * The doGet method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to get.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		this.doPost(request, response);
	}

	/**
	 * The doPost method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to post.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		response.setContentType("text/html");
		request.setCharacterEncoding("UTF-8");
		String path = request.getContextPath();
		String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
		
		String url = basePath + "/error.jsp";
		try{
			

			
			HttpSession session = request.getSession();
			
			BaseDM baseDM = input(request,session);
			
			executeCRUD(baseDM);
			
			List list = executeSearch(baseDM);
			
			request.setAttribute("resultList", list);
			
			url = output(request,list);
			
			initiateDropDown(request);
			
			forward(request,response,url);
			
			
		}catch(Exception err){
			forward(request,response,"/error.jsp");
		}

	}
	
	
	protected abstract BaseDM input(HttpServletRequest request,HttpSession session) throws FatalException;

	protected abstract String output(HttpServletRequest request,List list) throws FatalException;
	
	protected int executeCRUD(BaseDM baseDM) throws FatalException{
		return 0;
	}
	
	protected List executeSearch(BaseDM baseDM) throws FatalException{
		return null;
	}
	
	protected void initiateDropDown(HttpServletRequest request) throws FatalException {
		
	}
	
	private void forward(HttpServletRequest request,HttpServletResponse response,String url){
		RequestDispatcher rd = request.getRequestDispatcher(url);
		try {
			rd.forward(request, response);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			try {
				response.sendRedirect("error.jsp");
			} catch (IOException e1) {
				// TODO Auto-generated catch block
				e1.printStackTrace();
			}
		} 
	}


}